Explicit nonsymmetric robust cycling bound

Derive an explicit bound for robust perceptron cycling with a coercive nonsymmetric linear score operator, complementing the qualitative bound established for finite update sets and quantifying its dependence on the geometry of the update set and the skew-symmetric part of the operator.

Background

The main robust perceptron cycling theorem proves the existence of a constant C(E,U,A)C(E,U,A) controlling all approximate trajectories when the update set UU is finite, 0inconv⁡U0in\operatorname{conv}U, and the linear operator AA is coercive but not necessarily symmetric. The proof uses compactness and finite coverings, so the resulting constant is qualitative rather than explicit.

An explicit estimate is available in the symmetric positive-definite case through a relative-inradius argument. For nonsymmetric operators, the paper identifies the ratio between the skew-symmetric part and the smallest eigenvalue of the symmetric part as a natural parameter, but does not establish a uniform quantitative dependence on that ratio.

References

An explicit nonsymmetric counterpart remains to be derived.

— A Robust Perceptron Cycling Theorem and Applications  (2609.18342 - Harks, 16 Sep 2026) in Section 5, paragraph “Explicit constants”